The military application of aircraft to penetration missions, wherein a hostile territory is penetrated either for reconnaisance or weapon delivery purposes, has required that such aircraft fly a low-altitude flight path, maneuvering as necessary to avoid terrain obstacles. In this way, the penetrating vehicle is able to utilize such terrain for virtual and actual masking of the vehicle from detection by hostile ground-based radars, as described more fully in U.S. Pat. No. 3,360,794 issued Dec. 26, 1967, to C. E. Anderson, et al, for Terrain Avoidance System and also in U.S. Pat. No. 3,293,641 issued Dec. 20, 1966, to D. E. Bennett, et al, for Lateral Maneuver Indicator. Although such techniques tend to mask the penetrating vehicles from ground-based radars, such vehicles may yet be exposed to airborne detection systems onboard hostile interceptor aircraft. Such hostile systems may include doppler processing to distinquish a low-flying detected target from amid the clutter background against which the target is detected. Such doppler-processing may also be done by target tracking systems entirely contained within an air-to-air guided missile launched from the hostile vehicle, the vehicle's radar merely performing the function of illuminating the target or penetrating aircraft, as discussed more fully in U.S. Pat. No. 3,646,559 issued 02/29/72 for A Phase and Frequency Scanned Antenna by Carl A. Wiley, assignor to North American Rockwell Corporation, assignee of the subject invention.